In today's digital world, the use of graphical user interfaces (GUIs) to display and manage computer information has become ubiquitous. For example, the WINDOWS™ (Microsoft Corporation, Redmond, Wash.) operating systems used in many personal computers employs a GUI desktop with various icons or indicia representing objects on the computer system, and user input commands may be entered using keyboards, mice, etc. For these various types of input, there has traditionally been a direct correlation between directional orientation on the GUI and directional inputs on the input device. For example, pressing “up” on a keyboard key results in a corresponding upward movement of a cursor on the GUI.
This correlation helps provide an intuitive interface, but there is an inherent dependency required to provide the typical interface. Specifically, the designers of the system must assume that the input device, the GUI, and the display screen are all coordinated in terms of orientation. The GUI software counts on the “top” of the display screen as being the highest point of elevation from the user's point of view, while the keyboard designer assumes that the “up” arrow key should be mapped to movement towards the “top” of the GUI. In other words, the GUI software assumes the user will be viewing the screen from a certain orientation and certain point of view.
This assumption has suited traditional personal computing just fine, but the assumption begins to fail when a non-traditional display is used—such as a horizontally-oriented display surface (e.g., a table-top). Which way is “up” when the display is horizontal? What if 2, 3, or more people are standing around the display area at different locations? It would be an advance in the art if an alternative input mode could accommodate such differences in point of view.